Work-centering device for users of lathes.



R. H. FAY.

WORK GBNTBRING DEVICE FOR USERS 0F LATHES. APPLICATION FILED 0 0123,1907.

994,581 Patented June 6,1911;

\ wag ROBERT H. FAY, 0F CHICOPEE FALLS, MASSACHUSETTS.

WORK-CENTERING DEVICE FOR USERS OF LATHES.

Specification of Letters Patent.

Application filed October 28, 1907.

Patented June 6, 1911.

Serial No. 399,519.

To all whom it may concern:

7 Be it known that I, ROBERT H. FAY, a citizen of the United States ofAmerica, and resident of Chicopee Falls, in the county of Hampden andState of Massachusetts, have invented certain new and usefulImprovements in WorlcCentering Devices for Users of Lathes, of which thefollowing is a full, clear, and exact description.

The present invention resides in a small, generally circular device formaking the conical hole in a piece of work chucked at the head stock ofa lathe, into which conical hole in the work, and at the dead center ofthe lathe may be thereafter engaged the conical extremity of the tailstock center or dead center.

By the employment of the present device the centering of a piece of workmay be performed not only much easier, but also much quicker than hasheretofore been generally possible in pursuance of the heretofore knownmachine shop expedients.

The invention furthermore comprises an improved drill point and reamingtool having certain practical advantages as will be hereinafter renderedapparent.

The improved centering device is illustrated in the accompanyingdrawings in which,

Figure 1 is a side elevation showing the manner of utilizing the devicein connection with a piece of work chucked in a lathe. Fig. 2 is a sideelevation of the device on a larger scale. Fig. 3 is a front end view,and Fig. 4 is a longitudinal section as taken on line 4-4:, Fig. 3. Fig.5 is a very much enlarged cross sectional view taken on line 5-5, Fig.2. Fig. 6 is a perspective view of the parts constituting the improvedcombined drill and reamer. Fig. 7 is a side elevation of the combineddrill and reamer.

Similar characters of reference indicate corresponding parts in all ofthe views.

The device consists of a substantially cylindrical body A, preferablymilled or roughened peripherally whereby the same may be manually heldagainst rotation, having at the rear end thereof a conical socket a andhaving at its other end in axial alinement with said socket a forwardlyextending tool B for producing a conical centering hole in a rotativelycarried piece of work.

In Fig. l, 00 represents a'lathe of very common form, of which 3 is achuck rotatively carried at the head stock for carrystock.

ing the work to be turned or otherwise operatcd upon in the lathe,erepresenting the latter.

to represents the tail stock spindle or dead center understood ashaving, as usual, the conical end projecting toward the head The toolfor producing the conical center hole in the proper location in the endof the piece of work carried in the lathe chuck comprises a drillingpoint Z2 and a reamer 6Z,-tll6 cutting edge of which is to the rear ofthe drill point; and this combined drill and reamer is fitted and heldin an axial cylindrical bore 7 in the forward portion of the body A ofthe device.

In using the device to produce the conical socket or center in the work,into which thereafter the dead center to of the lathe tail stock may beengaged, it is only necessary for the machinist, after having run thetail stock in proper proximity to the end of the work, to engage the device by its conical rear end on the dead center 'w,the device naturallycentering itself axially by reason of the conical socket a seatingitself on the tapered end of the part w- Now while the work is rotating,the tail stock is run up so that the removably held drill and reamersuccessively operate to pro duce a centering hole in the end of thework, whereupon the tail stock is run slightly back to enable the personto disengage and remove the device from the work and from the deadcenter and then the tail stock is run up to bring its part to incentering and holding relation to the work. This operation manifestlymay be performed much more quickly than that heretofore followed inmounting a reaming and drilling tool in a chuck or holder therefor inthe tail stock spindle with necessity of imparting comparatively longmovements back and forth to the tail stock, of stopping to take out thedrill and reamer from the tail stock and having to thensubstitutetherefor the dead center.

Inasmuch as the taper of the dead centers of different la-thes may bevaried as to acuteness and also sometimes as to a departure from a truetapering form, as, for instance by being conoidal, I find itadvantageous to construct the portion of the body A in which the conicalrearwardly opening socket is formed, in two sections we and n, asparticularly represented in Figs. 2 and 4, one of which is axiallyadjustable relatively to the other by screw thread engagements as shownat 0. I also find it advantageous to free out or rabbet the wall of theconical socket a between the inner end and the mouth of such socket, asrepresented at t in Fig. 4, as conducing to the more ready and accurateseating of the centering device on lathe dead centers of variabletapers. By referring to Fig. 4, it will be observed that the projectionof the reaming tool forward of the body, is less in extent than thedepth of the conical socket a. In other words the seat ing depth of thebody exceeds the length of the cutting parts.

The combined drilland reamer as shown consists of the drill b and aplurality,-preferably no more than two,-of segmental members 10, 10,having longitudinal grooves 12 along their inner sides and slabbed facesfor a clamping fit about the shank of the drill, and having theirforward extremities inclined from their outer walls forwardly andinwardly toward the axial center, the so formed end portion of onesegmental member being endwise overlapped beyond the corresponding endportion of the other member to constitute a ream cutting edge 12 as moreclearly represented in Fig. 7. The ream centers 10, 10, and the drill intheir combined relations are held clamped in the bore f of the body A bythe binding screw 7'.

When a ream edge becomes bro-ken, worn or dull, it is not necessary todiscard the entire combined drill and reaming tool, for it is entirelypracticable and convenient, by loosening the screw j to remove the toolin its entirety, to grind the segmental ream tool sections and replacethem in their proper relations to each other and to the drill forcontinued usage; and many repeated grindings of the ream segments may beperformed as manifest; and again it is entirely practicable to replace aworn out drill for another as occasion may require.

1. A centering device consisting of a cylindrical body having a conicalcentering socket forming tool at and forwardly extended beyond theforward end, and having an axially located conical tail stock centerreceiving opening in the rear portion thereof, such portion of the bodycomprising such opening being constructed in sections, one of which isaxially adjustable relatively to the other.

2. A centering device composed of a short body having a conical socketat its rear end of sufficient depth to IGCBlXG the tail stock spindleand by manual holding of the body prevent lateral play of the devicewith re spect thereto, said body having a bore in its front end, aplurality of members secured in said bore and formed with drill holdingslots and a drill in said slots projecting beyond the front end of thebody, the extent of projection of the drill with respect to the bodybeing less than the depth of the conical socket.

Signed by me at Springfield, Mass, in presence of two subscribingwitnesses.

ROBERT H. FAY.

lVitnesses:

7M. S. BELLOWS, V a G. R. DRISCOLL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

